GB698655A - Improvements in dynamo electric generators - Google Patents

Abstract

698,655. Exciting D.C. generators. MACFARLANE, J. W., and MACFARLANE, W. I. May 2, 1952, No. 11117/52. Class 35. In a cross-flux amplifying generator having a short-span armature wind. ing, the normal excitation of the machine is done by main pole field coils ener. gized by a function of the generator output so that substantially no constant excitation current flows in the short-circuited quadrature axis, but only that required for control purposes. The machine is very similar to that described in Specification 566,168 except that in that machine the con. trol windings 10, 11 are arranged, when a continuous output is required, to be sufficiently out of balance to produce a continuous current in the short-circuited axis Q-Q which, in turn excites the main axis M-M to produce the required output at the main brushes X1, X2. In the present case the windings 10, 11 are mutually balanced in the absence of any signal and the load of continuous excitation is taken off the quadrature axis by the use of a selfexciting winding 12 in parallel or, as shown, in series with the continuous load terminals. The speed of reaction may be increased by the use of a transformer coupling from the main to the quadrature axis or by connecting a quadrature axis field winding in the short-circuit lead 7.